Electric cable system



Jan. 5, 1937. c. E. BENNETT ELECTRIC CABLE SYSTEM Filed 001;. 22, 1935 2Sheets-Sheet l INVENTOR 22 Z g I 1.

BY hm ATTORNEY 5 C. E, BENNETT ELECTRIC CABLE SYSTEM Jan. 5, 1937.

-Filed Oct. 22, 1935 k, Sheets-Sheet 2 INVENTOR 742. x v x IHUIIIIIIH mm m |lf|lx ll @0171 ATTORNEYS Patented Jan. 5, 1937 UNITED STATESELECTRIC CABLE SYSTEM Charles E. Bennett, Ridgewood, N. J., assignor toThe Okonite-Callender Cable Company, Incorporated, Paterson, N. .L, acorporation of New Jersey Application October 22, 1935, Serial No.46,064

Claims.

This invention relates to electric distribution systems particularlyadapted for use in connection with the distribution of power for streetlighting, house lighting and other domestic or commercial 5 loads, andhas for one of its objects the provision of a construction whereinoverhead lines are dispensed with, the feeder lines for the system beinginstalled underground in a pipe line filled with oil which is maintainedunder superatmospheric pressure, the step-down transformers by which thepower from the feeder lines is stepped down being installed directly inthe pipe line and submerged in the oil therein.

This invention presents many advantages both from an operating andconstruction viewpoint, as compared with existing systems; for example,it eliminates overhead lines, expensive manholes, the need for hightension transformer bushings, the cable being tapped to the bus whichserves 2 the transformer. Space requirements and installation costs arealso reduced to a minimum. The entire transformer construction is underoil and inside the pipe so that there are no external connections on thehigh side. This obviously eliminates the constant likelihood of breakingdown of a bushing and the transformer being submerged in oil will beproperly cooled. Inasmuch as the oil is under superatmospheric pressurethe transformer will be improved dielectrically. It 3 will beappreciated also that by installing the transformers directly in thepipe line with the cables, the expensive Y-joints and T-joints necessary in overhead lines as well as duct systems are eliminated. 35 Itwill be appreciated also that the present invention provides aconstruction by which the appearance of the property on which it isinstalled is materially improved, all equipment being buried. It will beappreciated also that heavy m'ain- 40 tenance costs due to treetrimming, damage caused by lightning in storms, changes in driveways,etc. on the property are eliminated by the present invention.

In the accompanying drawings:

Fig. 1 is a longitudinal section showing a section of my improved systemwith a transformer installed directly in the oil filled pipe line withthe cables;

Fig. 2 is a similar view showing the construction employed where it isdesirable to run a branch line at an angle to the main line;

Fig. 3 is a view of a modification of the structure of Fig. 2;

Fig. 4 is a plan view of a junction box employed in my improved system;and

Fig. 5 is a view taken substantially from the line 55 of Fig. 4.

Referring to the drawings in detail, my improved system comprises a pipeline I, preferably of metal, for example, and made in sections of 5 anydesired length depending upon the installation site. Drawn into thispipe line is a plurality of insulated conductors 2, suitably insulatedwith the customary paper insulation, for example, similar to thedisclosure of my copending 10 application Serial No. 666,032, filedApril 13, 1933.

The conductors 2 are connected to any suitable source of poweravailable, as will be understood.

At any desired intervals along the pipe line adjacent lengths or pipesections are left spaced 15 apart as shown in Fig. 1, for instance, andeach end of these adjacent sections of the pipe line is equipped with asleeve 3 which is attached to the pipe line in a liquid tight fashion bya coupler 4. Each of these couplers comprises a gland 5 surrounding thesleeve and welded or otherwise permanently attached thereto. At theextreme outer end of each of the sleeves 3 I provide a ring or disc 6.Each of these discs is cut back as shown at l to receive a metal cladwasher 8 which surrounds the pipe I. The disc 6 and gland 5 areconnected to each other by bolts 9 and when these bolts are drawn up aliquid tight seal is provided by the disc 6 and washer 8 between theouter end of each of the sleeves 3 and the outside of the pipe line I.

The adjacent ends of the sleeves 3 are left spaced apart as indicated inFig. 1, and the space thus provided is bridged or filled in by a sleeveI! which as shown on the drawings has its ends telescoped by the sleeves3.

A liquid tight connection is provided between the sleeve I2 and thesleeves 3 by couplers I3 and H which are similar to the couplers 4 abovereferred to.

It will be understood that these joints are provided at desiredintervals along the length of the system wherever desired, and they areprovided for the insertion directly into the pipe line I of thetransformers Ill. The primary winding of each transformer is connectedto the conductors 2 by splices such as shown at l I or in any othersuitable fashion. I

It will be understood that the three conductors 2 may be connected toeach transformer, or so that a pair of conductors may be connected to atransformer, another pair to the next transformer, and so on, the thirdconductor acting as a through connection. It is to be understood alsothat a transformer may not be installed at v each joint, the otherjoints being available in the future as the load demand on the systemincreases.

Each transformer is held in place in the pipe line by brackets 2i which,as illustrated in Fig. 1, are welded to the inside of the sleeve l2. Thelow tension side of each transformer i is provided with taps showndiagrammatically at which are brought out through the wall of the sleevel2 through sealing bushings 22. A housing 23 is bolted and sealed to theexterior of the sleeve 2 at these connections as shown in Fig. l. Theexternal circuits, as also shown in Fig. l, are wiped to the housing 23,their ends being coupled to the transformer leads within the housing.

The pipe line is filled with oil 24 maintained under superatmosphericpressure, of the order of 200 pounds to the square inch, for example, inwhich the transformers it! as well as the conductors 2 will at all timesbe submerged.

It will be seen that this construction possesses manyadvantages overprior practices, in which the transformers are separate and apart from Ithe cable system, it being necessary to run a separate line from thecable to the transformer, or if in a through circuit, to make a Y or aT- join't. It has been customary also in prior undergreund systems toinstall the transformers in a specially built manhole, which in thepractice of my invention are eliminated by reason of the fact that thetransformers are installed directly in the pipe line with the cableconductors. It

. will be appreciated also that to install the transformers in the cablepipe line is commercially feasible and practicable in that the oil willprovide for transformer cooling, and will improve the dielectriccharacteristics of the transformer. while the pipe line will be ofsufliciently rugged construction to protect the transformer againstinjury from outside sources.

It may be necessary or desirable in some instances to lay a branch lineat an angle to the pipe line i and in Figs. 2 and 3 I have shownconstructions particularly well adapted for this purpose. In thestructure of Fig. 2 it will be seen that the adjacent ends of twoadjacent lengths of the pipe line I are connected together by a sleeve25 which is provided with an offset 25 extending at an angle to thesleeve and which, as will be understood, is adapted to be joined to andconstitute a continuation of a pipe line which it is desired to lay atan angle to the pipe line I. The sleeve 2! and offset 28 are welded toeach other to constitute or provide a rigid construction and the sleeveis secured to the two adjacent pipe line sections I by couplers 21similar to the couplers 4, l3 and I4 above referred to.

Within the pipe line I and sleeve 25 I provide a construction wherebythe conductors 2 may be tapped so that the feeder conductors in theoffset 25 can be connected to the conductors within the pipe line. Thisconstruction comprises a central block of insulation, porcelain, forexample, designated 28, this block being provided with conducting rods29 which may be of copper, for instance, connections, shown at 2|, beingprovided in the block to the rods 20, the connections 30 extending tothe surface of the block 28 abreast of the end of the offset 28. Thefeeders in the offset 2i, it will be understood, are connected to theconnections ll.

Opposite ends of the block 28 are reduced in diameter as shown at ii toreceive bushings 12 which may be of porcelain, for instance, thesebushings fitting the ends of the sections of the pipe I, and eachbushing being provided with an annular flange 33 which bears against theend of the pipe line as shown in Fig. 4. These bushings fit over thereduced ends of the block 28 and are equipped with rods 34 which arecoupled to the rods 25 in the block 28. A bushing surrounds thesecouplers. These bushings 35 are of insulating material, porcelain forinstance, and screwed upon the end of the bushings 32.

The bushings 32 and block 28 are provided with a longitudinal passagewayor channel 36 to establish a through oil passage from one side of thestructure to the other, and the block 28 is provided with across-passage 31 for the passage of oil to the branch 26. When thisbranch is not in service, this passage 31 may be closed by a suitablevalve, or otherwise sealed.

The construction shown in Fig. 3 is quite similar to that shown and justdescribed in connection with Fig. 2. Here I have provided an offset 26'welded to a sleeve 25' attached in a liquid tight fashion to theadjacent ends of the two sections of the pipe line I. The central blockof this construction is designated 28 and each end of this blockreceives an insulating bushing 32'. The bushings 32 fit the inside ofthe pipe line I and each is provided with a conducting connector 34, oneend of each of which is connected to conducting rods 29 in the block28', the other end being coupled as shown to the conductors 2. A sleeveof insulating material 35 surrounds each of'these couplers, each ofthese sleeves being screwed upon the outer end of the bushings 32'.

The block 28' and bushings 32 are provided with longitudinal oil channel36 and the block with cross channel 31.

My improved system is provided with junction boxes illustrated in Figs.4 and 5 and designated 40. These junction boxes are primarily providedfor the purpose of sectionalizing the system, and as will be understoodare installed wherever desired along the pipe line. These boxes are notfilled with oil, the oil in the pipe line passing through the boxesthrough pipe 4|, which, as will be seen from Fig. 4, communicates withthe pipe line at each side of the box.

It will be understood that my improved system will be equipped withoverload circuit breakers or protective fuses.

It will be understood also that so far as branch lines are concerned,such as illustrated in Figs. 2 and 3, the cross channels 31 and 21' maybe sealed by suitable valves or in other fashion, should it be desiredto hold the branch line as a standby. It will be appreciated also thattransformers l0 may not be installed at all the joints as illustrated inFig. 1 on the original installation, transformers being installed lateras the load on the line increases.

It is to be understood that changes may be made in the details ofconstruction and arrangement of parts herein described, within the9111'- view of my invention.

What I claim is:-

i. In an electric distribution system, the combination of a feeder linecomprising a pipe line, insulated conductors and a transformer in thepipe, one winding of said transformer being connected to the saidconductors, transformer taps extending through the pipe line for theattachment of external branch circuits to another winding of saidtransformer, said taps being sealed into the wall of the pipe line, saidpipe line being filled with a body of oil under superatmosphericpressure which surrounds the said conductors and the said transformerand in which the conductors and transformer are at all times immersed.

2. In an electric distribution system, the combination of a feeder linecomprising a sectional pipe line, insulated conductors within said'pipeline, spaced sleeves sealed to the spaced adjacent ends of pipe linesections, a sleeve bridging the space between said first mentionedsleeves and sealed thereto, a transformer within the last mentionedsleeve mounted on a bracket secured to the interior of the said lastmentioned sleeve, one winding of said transformer being connected tosaid insulated conductors, the other winding of said transformer beingtapped and the taps extending through the last mentioned sleeve andsealed therein, and a body of oil under superatmospheric pressuresurrounding said conductors and transformer and in which saidconductorsand transformer are at all times immersed.

3. An electric distribution system comprising in combination a pipeline, insulated conductors and transformers within said pipe line, thetransformers being electrically connected to the cable conductors, abody of oil under superatmospheric pressure filling the pipe line andsurrounding said conductors and transformers, the said conductors andtransformers being immersed in said oil, a branch pipe line connectionfrom said pipe line for the reception of other cable conductors, meansfor coupling said last mentioned cable conductors to the first mentionedcable conductors, the said branch pipe line and the first mentioned pipeline communicating with each other whereby the said conductors andtransformers are surrounded by and immersed in the one body of oil. a

4. In an electric distribution system the combination of a sectionalpipe-line, cable conductors in the pipe line, the adjacent ends of someof the sections of said pipe line being disposed in spaced apartrelation, a sleeve surrounding the ends of such sections of the pipeline and secured liquid-tight thereto, said sleeve beingprovided with abranch extending at an angle to the main pipe line for the reception ofadditional cable conductors, and a fixture within said sleeve forcoupling the first mentioned cable conductors to the last mentionedcable conductors, said fixture being provided with a longitudinalchannel and a cross channel for oil whereby the main pipe line and thebranch line may be kept filled with oil under the same pressure.

, 5. An electric distribution system comprising in combination a pipeline, insulated conductors and transformers within said pipe line, thetransformers being connected to the conductors, said pipe line beingfilled with a body of oil maintained under superatmospheric pressuresurrounding said conductors and transformers and in which saidconductors and transformers 'are at all times immersed, junction boxesin said pipe line, and a pipe in each junction box for maintainingcommunication between the pipe line at one side. of the junction box andthe pipe line at the opposite side of the Junction box.

CHARLES

